i think they are waiting for next year. there are movies that had been developed longer before GFTB is filmed like Cronenberg's Cosmopolis but they set it out by the end of next year. Plus, Sundance isn't the only fest they have out there.

Maybe and this is a huge maybe, the producers wanted to sell the movie outside of the US first due to the other Jeff movie in production will make the selling of this movie in the US itself harder, its all the behind the scene politics. Now the selling of a movie outside is usually done if selling in Hollywood itself is hard. Because time is money and producers usually doesn't wait long to sell the movie, they can't sell in Hollywood yet but they need to sell somewhere. And usually, if they get huge buzz outside of Hollywood, they'll get into the US market faster.

BUT, Jeff Buckley is an American musician, so its pretty unlikely to sell outside of the US first.

Someone said about Cannes, well, its not unusual some of the Cannes people move around indie movies in development and picks it up for the festival before Sundance even had a chance to. Same goes to Berlin and Tiff.